Validation of key sponge symbiont pathways using genome-centric metatranscriptomics.

The sponge microbiome underpins host function through provision and recycling of essential nutrients in a nutrient poor environment. Genomic data suggest that carbohydrate degradation, carbon fixation, nitrogen metabolism, sulphur metabolism and supplementation of B-vitamins are central microbial functions. However, validation beyond the genomic potential of sponge symbiont pathways is rarely explored. To evaluate metagenomic predictions, we sequenced the metagenomes and metatranscriptomes of three common coral reef sponges: Ircinia ramosa, Ircinia microconulosa and Phyllospongia foliascens. Multiple carbohydrate active enzymes were expressed by Poribacteria, Bacteroidota and Cyanobacteria symbionts, suggesting these lineages have a central role in assimilating dissolved organic matter. Expression of entire pathways for carbon fixation and multiple sulphur compound transformations were observed in all sponges. Gene expression for anaerobic nitrogen metabolism (denitrification and nitrate reduction) were more common than aerobic metabolism (nitrification), where only the I. ramosa microbiome expressed the nitrification pathway. Finally, while expression of the biosynthetic pathways for B-vitamins was common, the expression of additional transporter genes was far more limited. Overall, we highlight consistencies and disparities between metagenomic and metatranscriptomic results when inferring microbial activity, while uncovering new microbial taxa that contribute to the health of their sponge host via nutrient exchange.

Testing cophylogeny between coral reef invertebrates and their bacterial and archaeal symbionts.

Marine invertebrates harbour a complex suite of bacterial and archaeal symbionts, a subset of which are probably linked to host health and homeostasis. Within a complex microbiome it can be difficult to tease apart beneficial or parasitic symbionts from nonessential commensal or transient microorganisms; however, one approach is to detect strong cophylogenetic patterns between microbial lineages and their respective hosts. We employed the Procrustean approach to cophylogeny (PACo) on 16S rRNA gene derived microbial community profiles paired with COI, 18S rRNA and ITS1 host phylogenies. Second, we undertook a network analysis to identify groups of microbes that were co-occurring within our host species. Across 12 coral, 10 octocoral and five sponge species, each host group and their core microbiota (50% prevalence within host species replicates) had a significant fit to the cophylogenetic model. Independent assessment of each microbial genus and family found that bacteria and archaea affiliated to Endozoicomonadaceae, Spirochaetaceae and Nitrosopumilaceae have the strongest cophylogenetic signals. Further, local Moran's I measure of spatial autocorrelation identified 14 ASVs, including Endozoicomonadaceae and Spirochaetaceae, whose distributions were significantly clustered by host phylogeny. Four co-occurring subnetworks were identified, each of which was dominant in a different host group. Endozoicomonadaceae and Spirochaetaceae ASVs were abundant among the subnetworks, particularly one subnetwork that was exclusively comprised of these two bacterial families and dominated the octocoral microbiota. Our results disentangle key microbial interactions that occur within complex microbiomes and reveal long-standing, essential microbial symbioses in coral reef invertebrates.

Asterix/Gtsf1 links tRNAs and piRNA silencing of retrotransposons.

The Piwi-interacting RNA (piRNA) pathway safeguards genomic integrity by silencing transposable elements (transposons) in the germline. While Piwi is the central piRNA factor, others including Asterix/Gtsf1 have also been demonstrated to be critical for effective silencing. Here, using enhanced crosslinking and immunoprecipitation (eCLIP) with a custom informatic pipeline, we show that Asterix/Gtsf1 specifically binds tRNAs in cellular contexts. We determined the structure of mouse Gtsf1 by NMR spectroscopy and identified the RNA-binding interface on the protein's first zinc finger, which was corroborated by biochemical analysis as well as cryo-EM structures of Gtsf1 in complex with co-purifying tRNA. Consistent with the known dependence of long terminal repeat (LTR) retrotransposons on tRNA primers, we demonstrate that LTR retrotransposons are, in fact, preferentially de-repressed in Asterix mutants. Together, these findings link Asterix/Gtsf1, tRNAs, and LTR retrotransposon silencing and suggest that Asterix exploits tRNA dependence to identify transposon transcripts and promote piRNA silencing.

Efficient COI barcoding using high throughput single-end 400 bp sequencing.

BACKGROUND: Over the last decade, the rapid development of high-throughput sequencing platforms has accelerated species description and assisted morphological classification through DNA barcoding. However, the current high-throughput DNA barcoding methods cannot obtain full-length barcode sequences due to read length limitations (e.g. a maximum read length of 300 bp for the Illumina's MiSeq system), or are hindered by a relatively high cost or low sequencing output (e.g. a maximum number of eight million reads per cell for the PacBio's SEQUEL II system). RESULTS: Pooled cytochrome c oxidase subunit I (COI) barcodes from individual specimens were sequenced on the MGISEQ-2000 platform using the single-end 400 bp (SE400) module. We present a bioinformatic pipeline, HIFI-SE, that takes reads generated from the 5' and 3' ends of the COI barcode region and assembles them into full-length barcodes. HIFI-SE is written in Python and includes four function modules of filter, assign, assembly and taxonomy. We applied the HIFI-SE to a set of 845 samples (30 marine invertebrates, 815 insects) and delivered a total of 747 fully assembled COI barcodes as well as 70 Wolbachia and fungi symbionts. Compared to their corresponding Sanger sequences (72 sequences available), nearly all samples (71/72) were correctly and accurately assembled, including 46 samples that had a similarity score of 100% and 25 of ca. 99%. CONCLUSIONS: The HIFI-SE pipeline represents an efficient way to produce standard full-length barcodes, while the reasonable cost and high sensitivity of our method can contribute considerably more DNA barcodes under the same budget. Our method thereby advances DNA-based species identification from diverse ecosystems and increases the number of relevant applications.

Diverse coral reef invertebrates exhibit patterns of phylosymbiosis.

Microbiome assemblages of plants and animals often show a degree of correlation with host phylogeny; an eco-evolutionary pattern known as phylosymbiosis. Using 16S rRNA gene sequencing to profile the microbiome, paired with COI, 18S rRNA and ITS1 host phylogenies, phylosymbiosis was investigated in four groups of coral reef invertebrates (scleractinian corals, octocorals, sponges and ascidians). We tested three commonly used metrics to evaluate the extent of phylosymbiosis: (a) intraspecific versus interspecific microbiome variation, (b) topological comparisons between host phylogeny and hierarchical clustering (dendrogram) of host-associated microbial communities, and (c) correlation of host phylogenetic distance with microbial community dissimilarity. In all instances, intraspecific variation in microbiome composition was significantly lower than interspecific variation. Similarly, topological congruency between host phylogeny and the associated microbial dendrogram was more significant than would be expected by chance across all groups, except when using unweighted UniFrac distance (compared with weighted UniFrac and Bray-Curtis dissimilarity). Interestingly, all but the ascidians showed a significant positive correlation between host phylogenetic distance and associated microbial dissimilarity. Our findings provide new perspectives on the diverse nature of marine phylosymbioses and the complex roles of the microbiome in the evolution of marine invertebrates.

Host-Microbe Coevolution: Applying Evidence from Model Systems to Complex Marine Invertebrate Holobionts.

Marine invertebrates often host diverse microbial communities, making it difficult to identify important symbionts and to understand how these communities are structured. This complexity has also made it challenging to assign microbial functions and to unravel the myriad of interactions among the microbiota. Here we propose to address these issues by applying evidence from model systems of host-microbe coevolution to complex marine invertebrate microbiomes. Coevolution is the reciprocal adaptation of one lineage in response to another and can occur through the interaction of a host and its beneficial symbiont. A classic indicator of coevolution is codivergence of host and microbe, and evidence of this is found in both corals and sponges. Metabolic collaboration between host and microbe is often linked to codivergence and appears likely in complex holobionts, where microbial symbionts can interact with host cells through production and degradation of metabolic compounds. Neutral models are also useful to distinguish selected microbes against a background population consisting predominately of random associates. Enhanced understanding of the interactions between marine invertebrates and their microbial communities is urgently required as coral reefs face unprecedented local and global pressures and as active restoration approaches, including manipulation of the microbiome, are proposed to improve the health and tolerance of reef species. On the basis of a detailed review of the literature, we propose three research criteria for examining coevolution in marine invertebrates: (i) identifying stochastic and deterministic components of the microbiome, (ii) assessing codivergence of host and microbe, and (iii) confirming the intimate association based on shared metabolic function.

Elevated CO2 Has Little Influence on the Bacterial Communities Associated With the pH-Tolerant Coral, Massive Porites spp.

Ocean acidification (OA) as a result of increased anthropogenic CO2 input into the atmosphere carries consequences for all ocean life. Low pH can cause a shift in coral-associated microbial communities of pCO2-sensitive corals, however, it remains unknown whether the microbial community is also influenced in corals known to be more tolerant to high pCO2/low pH. This study profiles the bacterial communities associated with the tissues of the pCO2-tolerant coral, massive Porites spp., from two natural CO2 seep sites in Papua New Guinea. Amplicon sequencing of the hypervariable V3-V4 regions of the 16S rRNA gene revealed that microbial communities remained stable across CO2 seep sites (pH = 7.44-7.85) and adjacent control sites (ambient pH = 8.0-8.1). Microbial communities were more significantly influenced by reef location than pH, with the relative abundance of dominant microbial taxa differing between reefs. These results directly contrast with previous findings that increased CO2 has a strong effect on structuring microbial communities. The stable structure of microbial communities associated with the tissues of massive Porites spp. under high pCO2/low pH conditions confirms a high degree of tolerance by the whole Porites holobiont to OA, and suggest that pH tolerant corals such as Porites may dominate reef assemblages in an increasingly acidic ocean.

TROSY pulse sequence for simultaneous measurement of the 15N R1 and {1H}-15N NOE in deuterated proteins.

A TROSY-based NMR experiment is described for simultaneous measurement of the 15N longitudinal relaxation rate constant R1 and the {1H}-15N nuclear Overhauser enhancement. The experiment is based on the observation that the TROSY mixing pulse sequence element symmetrically exchanges 1H and 15N magnetizations. The accuracy of the proposed technique is validated by comparison to independent measurements of both relaxation parameters for the protein ubiquitin. The simultaneous experiment is approximately 20-33% shorter than conventional sequential measurements.

Intrauterine insemination versus intracervical insemination in donor sperm treatment.

BACKGROUND: The first-line treatment in donor sperm treatment consists of inseminations that can be done by intrauterine insemination (IUI) or by intracervical insemination (ICI). OBJECTIVES: To compare the effectiveness and safety of intrauterine insemination (IUI) and intracervical insemination (ICI) in women who start donor sperm treatment. SEARCH METHODS: We searched the Cochrane Gynaecology and Fertility Group Trials Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL in October 2016, checked references of relevant studies, and contacted study authors and experts in the field to identify additional studies. We searched PubMed, Google Scholar, the Grey literature, and five trials registers on 15 December 2017. SELECTION CRITERIA: We included randomised controlled trials (RCTs) reporting on IUI versus ICI in natural cycles or with ovarian stimulation, and RCTs comparing different cointerventions in IUI and ICI. We included cross-over studies if pre-cross-over data were available. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by Cochrane. We collected data on primary outcomes of live birth and multiple pregnancy rates, and on secondary outcomes of clinical pregnancy, miscarriage, and cancellation rates. MAIN RESULTS: We included six RCTs (708 women analysed) on ICI and IUI in donor sperm treatment. Two studies compared IUI and ICI in natural cycles, two studies compared IUI and ICI in gonadotrophin-stimulated cycles, and two studies compared timing of IUI and ICI. There was very low-quality evidence; the main limitations were risk of bias due to poor reporting of study methods, and serious imprecision.IUI versus ICI in natural cyclesThere was insufficient evidence to determine whether there was any clear difference in live birth rate between IUI and ICI in natural cycles (odds ratio (OR) 3.24, 95% confidence interval (CI) 0.12 to 87.13; 1 RCT, 26 women; very low-quality evidence). There was only one live birth in this study (in the IUI group). IUI resulted in higher clinical pregnancy rates (OR 6.18, 95% CI 1.91 to 20.03; 2 RCTs, 76 women; I² = 48%; very low-quality evidence).No multiple pregnancies or miscarriages occurred in this study.IUI versus ICI in gonadotrophin-stimulated cyclesThere was insufficient evidence to determine whether there was any clear difference in live birth rate between IUI and ICI in gonadotrophin-stimulated cycles (OR 2.55, 95% CI 0.72 to 8.96; 1 RCT, 43 women; very low-quality evidence). This suggested that if the chance of a live birth following ICI in gonadotrophin-stimulated cycles was assumed to be 30%, the chance following IUI in gonadotrophin-stimulated cycles would be between 24% and 80%. IUI may result in higher clinical pregnancy rates than ICI (OR 2.83, 95% CI 1.38 to 5.78; 2 RCTs, 131 women; I² = 0%; very low-quality evidence). IUI may be associated with higher multiple pregnancy rates than ICI (OR 2.77, 95% CI 1.00 to 7.69; 2 RCTs, 131 women; I² = 0%; very low-quality evidence). This suggested that if the risk of multiple pregnancy following ICI in gonadotrophin-stimulated cycles was assumed to be 10%, the risk following IUI would be between 10% and 46%.We found insufficient evidence to determine whether there was any clear difference between the groups in miscarriage rates in gonadotrophin-stimulated cycles (OR 1.97, 95% CI 0.43 to 9.04; 2 RCTs, overall 67 pregnancies; I² = 50%; very low-quality evidence).Timing of IUI and ICIWe found no studies that reported on live birth rates.We found a higher clinical pregnancy rate when IUI was timed one day after a rise in blood levels of luteinising hormone (LH) compared to IUI two days after a rise in blood levels of LH (OR 2.00, 95% CI 1.14 to 3.53; 1 RCT, 351 women; low-quality evidence). We found insufficient evidence to determine whether there was any clear difference in clinical pregnancy rates between ICI timed after a rise in urinary levels of LH versus a rise in basal temperature plus cervical mucus scores (OR 1.31, 95% CI 0.42 to 4.11; 1 RCT, 56 women; very low-quality evidence).Neither of these studies reported multiple pregnancy or miscarriage rates as outcomes. AUTHORS' CONCLUSIONS: There was insufficient evidence to determine whether there was a clear difference in live birth rates between IUI and ICI in natural or gonadotrophin-stimulated cycles in women who started with donor sperm treatment. There was insufficient evidence available for the effect of timing of IUI or ICI on live birth rates. Very low-quality data suggested that in gonadotrophin-stimulated cycles, ICI may be associated with a higher clinical pregnancy rate than IUI, but also with a higher risk of multiple pregnancy rate. We concluded that the current evidence was too limited to choose between IUI or ICI, in natural cycles or with ovarian stimulation, in donor sperm treatment.

Enhanced spectral density mapping through combined multiple-field deuterium 13CH2D methyl spin relaxation NMR spectroscopy.

Quadrupolar relaxation of 2H (D) nuclear spins is a powerful probe of conformational dynamics in biological macromolecules. Deuterium relaxation rate constants are determined by the spectral density function for reorientation of the C-D bond vector at zero, single-quantum, and double-quantum 2H frequencies. In the present work, 2H relaxation rate constants were measured for an E. coli ribonuclease H [U-2H, 15N] ILV-[13CH2D] sample using 400, 500, 800, and 900 MHz NMR spectrometers and analyzed by three approaches to determine spectral density values. First, data recorded at each static magnetic field were analyzed independently. Second, data recorded at 400 and 800 MHz were analyzed jointly and data recorded at other fields were analyzed independently. Third, data recorded at 400 and 500 MHz were interpolated to 450 MHz, and the resulting two pairs of data, corresponding to 400 MHz/800 MHz and 450 MHz/900 MHz, were analyzed jointly. The second and third approaches rely on the identity between the double quantum frequency at the lower field and the single quantum frequency at the higher field. Spectral density values for 32 of the 48 resolvable ILV methyl resonances were fit by the Lipari-Szabo model-free formalism and used to validate the three methods. The three spectral density mapping methods performed equally well in cross validation with data recorded at 700 MHz. However, the third method yielded approximately 10-15% more precise estimates of model-free parameters and consequently provides a general strategy for analysis of 2H spin relaxation data in biological macromolecules.

Uterine perforation by intrauterine devices: a 16-year review.

INTRODUCTION: One of the major concerns with the insertion of intrauterine devices is uterine perforation. Though uncommon, it can be debilitating and result in failure of the device. In this article we review uterine perforation with intrauterine contraception (IUC) in a community clinic in the UK over a 16-year period. METHODS: We prospectively collected data on uterine perforations for the years 2000-2015, reviewed associated factors and calculated the annual rate of perforation, estimating if this lay within the expected range of normal variation using statistical process control (SPC) analysis. We analysed the rates of perforation in relation to the time from delivery and to breastfeeding. RESULTS: We identified 30 uterine perforations in 22 795 IUC insertions over the 16 years of observation, with an annual rate ranging from 0 to 4.3 per 1000 insertions, and a mean annual rate of 1.3 per 1000 insertions (95% CI 0.9 to 1.9), which remain within the SPC limits. Twenty-eight of the perforations were in parous women, 87% of whom were within 18 weeks of delivery, peaking at 13 weeks postpartum. Twenty of these were in breastfeeding women. In 3/28 cases for which we have outcome data the device was adherent to or had perforated either the bladder or bowel. CONCLUSION: Our perforation rate is consistent with other studies. Most of our perforations were within 18 weeks of childbirth, earlier than in a recent major study. We cannot tell from our data if there is a true peak in perforations 3 months postpartum as that may be a time when a high proportion of insertions are done.

Interventions for pain with intrauterine device insertion.

BACKGROUND: Fear of pain during insertion of intrauterine contraception (IUC) is a barrier to use of this method. IUC includes copper-containing intrauterine devices and levonorgestrel-releasing intrauterine systems. Interventions for pain control during IUC insertion include non-steroidal anti-inflammatory drugs (NSAIDs), local cervical anesthetics, and cervical ripening agents such as misoprostol. OBJECTIVES: To review randomized controlled trials (RCTs) of interventions for reducing IUC insertion-related pain SEARCH METHODS: We searched for trials in CENTRAL, MEDLINE, EMBASE, POPLINE, ClinicalTrials.gov, and ICTRP. The most recent search was 22 June 2015. We examined reference lists of pertinent articles. For the initial review, we wrote to investigators to find other published or unpublished trials. SELECTION CRITERIA: We included RCTs that evaluated an intervention for preventing IUC insertion-related pain. The comparison could have been a placebo, no intervention, or another active intervention. The primary outcomes were self-reported pain at tenaculum placement, during IUC insertion, and after IUC insertion (up to six hours). DATA COLLECTION AND ANALYSIS: Two authors extracted data from eligible trials. For dichotomous variables, we calculated the Mantel-Haenszel odds ratio (OR) with 95% confidence interval (CI). For continuous variables, we computed the mean difference (MD) with 95% CI. In meta-analysis of trials with different measurement scales, we used the standardized mean difference (SMD). MAIN RESULTS: We included 33 trials with 5710 participants total; 29 were published from 2010 to 2015. Studies examined lidocaine, misoprostol, NSAIDs, and other interventions. Here we synthesize results from trials with sufficient outcome data and moderate- or high-quality evidence.For lidocaine, meta-analysis showed topical 2% gel had no effect on pain at tenaculum placement (two trials) or on pain during IUC insertion (three trials). Other formulations were effective compared with placebo in individual trials. Mean score for IUC-insertion pain was lower with lidocaine and prilocaine cream (MD -1.96, 95% CI -3.00 to -0.92). Among nulliparous women, topical 4% formulation showed lower scores for IUC-insertion pain assessed within 10 minutes (MD -15.90, 95% CI -22.77 to -9.03) and at 30 minutes later (MD -11.10, 95% CI -19.05 to -3.15). Among parous women, IUC-insertion pain was lower with 10% spray (median 1.00 versus 3.00). Compared with no intervention, pain at tenaculum placement was lower with 1% paracervical block (median 12 versus 28).For misoprostol, meta-analysis showed a higher mean score for IUC insertion compared with placebo (SMD 0.27, 95% CI 0.07 to 0.46; four studies). In meta-analysis, cramping was more likely with misoprostol (OR 2.64, 95% CI 1.46 to 4.76; four studies). A trial with nulliparous women found a higher score for IUC-insertion pain with misoprostol (median 46 versus 34). Pain before leaving the clinic was higher for misoprostol in two trials with nulliparous women (MD 7.60, 95% CI 6.48 to 8.72; medians 35.5 versus 20.5). In one trial with nulliparous women, moderate or severe pain at IUC insertion was less likely with misoprostol (OR 0.30, 95% CI 0.16 to 0.55). In the same trial, the misoprostol group was more likely to rate the experience favorably. Within two trials of misoprostol plus diclofenac, shivering, headache, or abdominal pain were more likely with misoprostol. Participants had no vaginal delivery. One trial showed the misoprostol group less likely to choose or recommend the treatment.Among multiparous women, mean score for IUC-insertion pain was lower for tramadol 50 mg versus naproxen 550 mg (MD -0.63, 95% CI -0.94 to -0.32) and for naproxen versus placebo (MD -1.94, 95% CI -2.35 to -1.53). The naproxen group was less likely than the placebo group to report the insertion experience as unpleasant and not want the medication in the future. An older trial showed repeated doses of naproxen 300 mg led to lower pain scores at one hour (MD -1.04, 95% CI -1.67 to -0.41) and two hours (MD -0.98, 95% CI -1.64 to -0.32) after insertion. Most women were nulliparous and also had lidocaine paracervical block. AUTHORS' CONCLUSIONS: Nearly all trials used modern IUC. Most effectiveness evidence was of moderate quality, having come from single trials. Lidocaine 2% gel, misoprostol, and most NSAIDs did not help reduce pain. Some lidocaine formulations, tramadol, and naproxen had some effect on reducing IUC insertion-related pain in specific groups. The ineffective interventions do not need further research.

Progestin-only pills for contraception.

BACKGROUND: The introduction of a new progestin-only oral contraceptive in Europe has renewed interest in this class of oral contraceptives. Unlike the more widely used combined oral contraceptives containing an estrogen plus progestin, these pills contain only a progestin (progestogen) and are taken without interruption. How these pills compare to others in their class or to combined oral contraceptives is not clear. OBJECTIVES: This review examined randomized controlled trials of progestin-only pills for differences in efficacy, acceptability, and continuation rates. SEARCH METHODS: Through October 2013, we searched the computerized databases MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), POPLINE, and LILACS for studies of progestin-only pills. We also searched for current trials via ClinicalTrials.gov and ICTRP. Previous searches also included EMBASE. SELECTION CRITERIA: We included all randomized controlled trials in any language that included progestin-only pills for contraception.  We incorporated any comparison with a progestin-only pill; this could include different doses, other progestin-only pills, combined oral contraceptives, or other contraceptives. DATA COLLECTION AND ANALYSIS: The first author abstracted the data and entered the information into RevMan 5. Another author performed a second, independent data abstraction to verify the initial data entry.We attempted to extract life-table rates (actuarial or continuous) and used the rate difference as the effect measure. Where life-table rates were not published, we used the incidence rate ratio (ratio of Pearl rates). Where only the crude number of events was published, we calculated the Peto odds ratio with 95% confidence interval (CI) using a fixed-effect model. For continuous variables, the mean difference (MD) was computed with 95% CI. Because of disparate exposures, we were not able to combine studies in meta-analysis. MAIN RESULTS: Six trials met the inclusion criteria. We have not found any new studies since the initial review. In the trial comparing the desogestrel versus levonorgestrel progestin-only pill, desogestrel was not associated with a significantly lower risk of accidental pregnancy; the rate ratio was 0.27 (95% CI 0.06 to 1.19). However, the desogestrel progestin-only pill caused more bleeding problems, although this difference was not statistically significant. The trial comparing low-dose mifepristone versus a levonorgestrel progestin-only pill found similar pregnancy rates. In the trial comparing ethynodiol diacetate versus a combined oral contraceptive, irregular cycles occurred in all women assigned to the progestin-only pill (odds ratio 135.96; 95% CI 7.61 to 2421.02). In a trial comparing two progestin-only and two combined oral contraceptives, the progestin-only pill containing levonorgestrel 30 µg had higher efficacy than did the pill containing norethisterone 350 µg. An early trial found megestrol acetate inferior to other progestin-only pills in terms of efficacy. A study of the timing of pill initiation after birth found no important differences, but high losses to follow up undermined the trial. AUTHORS' CONCLUSIONS: Evidence is insufficient to compare progestin-only pills to each other or to combined oral contraceptives.

Progestin-only pills for contraception.

BACKGROUND: The introduction of a new progestin-only oral contraceptive in Europe has renewed interest in this class of oral contraceptives. Unlike the more widely used combined oral contraceptives containing an estrogen plus progestin, these pills contain only a progestin (progestogen) and are taken without interruption. How these pills compare to others in their class or to combined oral contraceptives is not clear. OBJECTIVES: This review examined randomized controlled trials of progestin-only pills for differences in efficacy, acceptability, and continuation rates. SEARCH STRATEGY: We searched the computerized databases MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), POPLINE, LILACS, and EMBASE for studies of progestin-only pills. We also searched for current trials via ClinicalTrials.gov and ICTRP. SELECTION CRITERIA: We included all randomized controlled trials in any language that included progestin-only pills for contraception. We incorporated any comparison with a progestin-only pill; this could include different doses, other progestin-only pills, combined oral contraceptives, or other contraceptives. DATA COLLECTION AND ANALYSIS: The first author abstracted the data and entered the information into RevMan 5. Another author performed a second, independent data abstraction to verify the initial data entry. Because of disparate exposures, we were not able to combine studies in meta-analysis. MAIN RESULTS: Six trials met the inclusion criteria. In the trial comparing the desogestrel versus levonorgestrel progestin-only pill, desogestrel was not associated with a significantly lower risk of accidental pregnancy; the rate ratio was 0.27 (95% CI 0.06 to 1.19). However, the desogestrel progestin-only pill caused more bleeding problems, although this difference was not statistically significant. The trial comparing low-dose mifepristone versus a levonorgestrel progestin-only pill found similar pregnancy rates. In the trial comparing ethynodiol diacetate versus a combined oral contraceptive, irregular cycles occurred in all women assigned to the progestin-only pill (odds ratio 135.96; 95% CI 7.61 to 2421.02). In a trial comparing two progestin-only and two combined oral contraceptives, the progestin-only pill containing levonorgestrel 30 mug had higher efficacy than did the pill containing norethisterone 350 mug. An early trial found megestrol acetate inferior to other progestin-only pills in terms of efficacy. A study of the timing of pill initiation after birth found no important differences, but high losses to follow up undermined the trial. AUTHORS' CONCLUSIONS: Evidence is insufficient to compare progestin-only pills to each other or to combined oral contraceptives.

Elastic constants of hard thin platelets by Monte Carlo simulation and virial expansion.

In this paper we present an investigation into the calculation of the Frank elastic constants of hard platelets via molecular simulation and virial expansion beyond second order. Monte Carlo simulations were carried out and director fluctuations measured as a function of wave vector k, giving the elastic constants through a fit in the low-k limit. Additionally, the virial expansion coefficients of the elastic constants up to sixth order were calculated, and the validity of the theory determined by comparison with the simulation results. The simulation results are also compared with experimental measurements on colloidal suspensions of platelike particles.

Copper-containing, framed intrauterine devices for contraception: a systematic review of randomized controlled trials.

BACKGROUND: Intrauterine devices (IUDs) are safe and effective methods of long-term reversible contraception. The design and copper content as well as placement of the copper on IUDs could affect their effectiveness and side effect profile. We compared different copper IUDs for their effectiveness and side effects. STUDY DESIGN: We searched multiple electronic databases with appropriate keywords and names of the IUDs known to be on the market. We searched the reference lists of papers identified and contacted authors when possible. There was no language restriction. Randomized controlled trials comparing different IUDs that reported on clinical outcomes were considered for inclusion. Two reviewers independently extracted data on outcomes and trial characteristics. We combined the trial results in meta-analyses and expressed results as rate difference (RD) using a fixed-effects model with 95% confidence interval (CI). In the presence of significant heterogeneity, a random-effects model was applied. RESULTS: We included 35 trials, resulting in 18 comparisons of 10 different IUDs in approximately 48,000 women. TCu380A was more effective in preventing pregnancy than MLCu375 (RD 1.70%, 95% CI 0.07-2.95% after 4 years of use). TCu380A was also more effective than MLCu250, TCu220 and TCu200. There tended to be fewer pregnancies with TCu380S compared to TCu380A after the first year of use, a difference which was statistically significant in the fourth year (RD -1.62%, 95% CI -3.00% to -0.24%). This occurred despite more expulsions with TCu380S (RD 3.50%, 95% CI 0.36-6.63% at 4 years). MLCu375 was no more effective than TCu220 at 1 year of use, or MLCu250 and NovaT up to 3 years. Compared to TCu380A or TCu380S, none of the IUDs showed any benefits in terms of bleeding or pain or any of the other reasons for early discontinuation. None of the trials that reported events at insertion found one IUD easier to insert than another or caused less pain at insertion. There is no evidence that uterine perforation rates vary by type of device. There are minimal randomized data on IUD use in nulliparous women. CONCLUSIONS: TCu380A and TCu380S appear to be more effective than other IUDs. No IUD showed consistently lower removal rates for bleeding and pain in comparison to other IUDs. There is no evidence that any particular framed copper device is better suited to women who have not had children.